Process of making filamentous lead.



0. ELLIS.

rnoonss or MAKING FILAMENTOUS LEAD.

APPLICATION FILED J AH.27, 1908.

Patented Mar. 29, 1910.

Wmmssw. Xxwmmv WMWMA m UNITED STATES PATENT OFFICE.

CARLETON ELLIS, F LARCHMONT, NEW YORK, ASSIGNOR TO ELLIS-FOSTER COMPANY,

A CORPORATION OF NEW JERSEY.

PROCESS OF MAKING FILAIVIENTOUS LEAD.

Specification of Letters Patent.

Patented Mar. 29, 1910.

Application filed January 27, 1908. Serial No. 412,933.

To all whom 'it 'may concern:

Be it known that I, Canmrrox ELLIS, citizen of the United States, residing at Larchmont, in the county of Wcstchester and State of New York, have invented certain new and useful Improvements in Proc- 1 esses of Making l i1an'1eutous Lead, of which the followmg 1s a specification.

This invention relates to the process of treating metallic lead to put it in the form of a finely divided filamentous material preferably substantially unoxidized, for the purpose of subsequently oxidizing and carand bonating, to make white lead pigment other lead pigments.

The customary method of treating lead in the so-called rapid process of lead corrosion, 1

is to force molten lead through small orifices to produce fine cylindrical rods of the metal, F which are subsequ tly subjected to corro- I sion. It has also een suggested that the lead be deposited electrically to produce a spon y material which may dized to produce pigments. processes afiord a material which 1s be rapidly oxi- Neither of these capable of being oxidized with extreme rapidity to form a perfectly pure and clean pigment.

The present invention has for its particular object the production of filamentous lead which is capable of being corroded with extreme rapidity to make a pigment having 7 properties desired.

- phere consisting largely the high degree of opacity and pigmentary In carrying out my invention, I put the lead into a super-molten condition, by heating in a suitable receptacle to approximately 200 above the meltin point of the lead, and force said molten lead in a fine stream past a jet of inert gases issuing from an once under pressure. The gases whlch I prefer to employ are those which are derived from the initial oxidation of lead by passage of air thereover, so as to produce an atmosof nitrogen. This I the stream of molten accomplish by allowing lead to be impinged upon by the jet in a withdrawing the gases 3 closed receptacle, from said receptacle and forcmg them by means of a suitable blower or compressor through the jet orifice.

By referring to the accompanylng drawing, the manner in which my invention is carried out, will be evident.

In the drawing, 1-- re resents a lead melting pot having the heatmg furnace-2.

l roding process.

; The melting pot is preferably closed by the 1 cover -3, through which air under pressure I may be introduced, if desired, through the l pipe 4; 5- is a pipe leading from the bottom of the melting pot 1, into a closed chamber 6; this pipe is fitted with the valve '7; at 8- is situated a jet nozzle, throu h which the gases under pressure enter. The intake of these gases is at -9, from which, by means of the system pipe 10, cooler 11, compressor 12 and chamber 13, the gases are forced through the jet nozzle.

14- is a dampered hopper for the removal of the filamentous lead.

In operating the apparatus in accordance with my process, the lead, when suitably melted, is allowed to discharge into the closed chamber, while the compressor is in operation, thereby breakin up the lead stream and-causing the lead to takea filamentous form. This lead material deposits j on the floor of the closed receptacle and is removed by operating the dampered hopper. 'hen the ap )aratus is first ut into operation, if the chamber is fillet? initially with air, some oxidation of the very first portion of the lead entering the chamber'occurs, and this material may be rejected, if desired. Very soon, however, the atmosphere of the chamber becomes so impoverished as regards its content of oxygen, that further oxidation of the lead does not take place, and the metal is thrown into a filamentous condition, clean and free from superficial oxidation. If desired, the receptacle at the start may be filled with an inert gas, such as nitrogen roducts of combustion, producer gas, and t e like. The process may be made continuous, by having several melting pots, so that when one is emptied, another pot may immediately be caused to discharge into the filamentary chamber. In using producer gas as the inert gaseous fluid, it is desirable to wash same thoroughly, which may be accomplished by means of a suitable scrubber; as otherwise particles of carbon or tar might contaminate the lead product.

The lead is preferably injected nto the filamenting chamber in a super-molten condition, as under such circumstances, the filaments produced are excessively fine and are far more susceptible to the white lead cor- When the lead is introduced at a temperature only a few degrees above the melting point of the metal, the filaments are coarser. A temperature of at last 200 degrees above the melting point is therefore to be recommended, as with such temperatures the metal is in the proper super-molten condition for filamenting. The filamentous lead so produced may then be subjected to corrosion in pots, such as are used in the Dutch process, or treated, or corroded, in any other suitable manner.

By using a current of air only, the lead may be' oxidized largely to red lead, or litharge, producing pigments, when further corroded, having'unnsual shades of color.

Owing to the temperature of the gases ithdrawn from the filamenting chamber, it is often times desirable to introduce a cooler in'the pipe line leading to the compressor. Steam may be used in wholezor in part in the filamenting chamber, as the gaseous filamenting fluid, in which case when superheated steam and lead in ahighly,

- super-molten condition are used, oxidation takes place to some extent, producing a superficially oxidized lead filament.

To recapitulate: My invention consists in the treatment of molten lead preferably in a super-molten state with an impinging jet of gaseous fluid, preferably of an nert character, to produce metallic lead in a filamentous condition.

Having described my invention, to the details of which descrlption, I do not, vof course, wish to be limited, what I claim as my invention is 1. The process of making an easily oxidizable lead which consists in exposinga stream of metallic lead in a super-molten condition to a jet of compressed inert gases,

l l l whereby lead in a'filamentous condition is produced.

2. The process of making easily oxidizable lead, which consists in subjecting supermolten lead to a jet of com ressed gases, whereby the metal is converte into material of a filamentous character.

3. The process of making easily oxidizable lead, which consists in subjecting a fine stream of super-molten lead to the filamenting action of an impinging jet of inert gases under pressure in a closed receptacle, whereby lead in a finely divided filamentous condition is produced.

4. The process of producing easily oxidizable lead material, which consists in subjecting a fine stream of melted lead in a super-molten condition to the filamenting action of a jet of compressed inert gases,

directed into impingement upon said lead.

stream; said gases -bein derived from the gaseous products resultlng from the prlor passage of air through sald lead material:

whereby finelydivided filamentous lead is produced.

5. The process of making easily oxidizable lead, which consists in subjecting supermolten lead at-a temperature approximating 200 above its melting point to the impinging action of a jet of compressed inert gas, whereby the metal is converted into material of a filamentous character.

In testimony whereof I have afiixed my signature in presence of tWo Witnesses.

CARLETON ELLIS.

Witnesses :v

NATHANIEL L. FOSTER, HENRIETTA BERKWITZ. 

